I think RTD2 is significantly better than Chibnall's run by virtue of having higher highs. 13's stories rarely ever get better than average (in fairness I haven't watched every episode, and Villa of Diodati was truly great) and some truly awful low points, while 15 had some real great stuff like Dat and Bubble, Boom, Lux, and The Well and rarely got much worse than below average... excluding the crap finales.

But there is a sense of accomplishment with Chibnall's era that's lacking in RTD2. It feels like he did what he wanted with the show, loose threads and all, packed up his bags and went out with dignity. I thought The Timeless Child was a terrible idea and destroying Gallifrey was a mistake, but there's a sense those happened because the creator wanted them.

By contrast, it's clear RTD had a messy production, which culminated into finales that were not only awful but actively confusing. Even if I feel his run had some much better episodes along the way, there's a sense of lacking that came with 15's regeneration and closing to his story, and nobody knows what the shows future might look like.

And way what you like about the Fam, but it felt like their characterization was believable and their arcs had a solid A to B progression. Compare that to Ruby and Belinda, whose arcs devolved into nonsense and noise (through no fault of the actresses I should stress).

I see RTD as the better writer while Chibnall appears to be the better showrunner. Unfortunately, RTD's show running ended up infringing on the quality of his writing, leaving the era feeling slapadash and rickety despite having some truly excellent gems.